Conventional imaging systems receive power from one or more sources. The sources include batteries and an external alternating current (AC) power source coupled to electrical wall outlets. For many imaging systems, the primary source of power is the external AC power source coupled to electrical wall outlets.
However, certain functions of the imaging systems draw more power than can be supplied through the typical conventional electrical wall outlet. In particular, advanced mobile healthcare imaging systems may require more power than can be obtained from a conventional electrical wall outlet. For example, a mobile imaging system used for computed tomography (CT) or three-dimensional (3D) image reconstruction may need to energize motors for moving subsystems, provide power for the high voltage X-ray generation, provide active cooling for heat dissipation of the X-ray acquisition subsystem, power all other image processing and display subsystems, power interface and archiving devices, etc.
In the United States, AC power available at electrical wall outlets is conventionally limited to 15 amps and 115 volts. Standards from the International Electrotechnical Committee (IEC) located in Geneva Switzerland and other standards and regulations further limit the current from 15 amps to 12 amps, or 13.2 amps in the case of X-ray equipment. Alternate electrical wall outlets located in some facilities will allow up to 17.6 amps. Thus, the power that can be drawn from a 115 volt outlet can vary from 1400 to 2000 watts (the product of voltage and current), which is lower than is needed by the imaging system during operations discussed above.
In some conventional imaging systems, rechargeable battery pack(s) are used to augment power from the electrical wall outlet. The battery pack(s) provide intermittent short-term power when the imaging system requires more electrical power than the electrical wall outlet can supply. The batteries are recharged between high power events. This method is effective as long as the long-term average power draw from the battery charger and other electronic devices in the imaging system is below the electrical wall outlet power level that is allowed. Note also that separate electrical wall outlets in close proximity to each other may typically be wired on the same circuit, and so ampacity remains a concern.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a power source to an imaging system that draws less power on average from a conventional electrical wall outlet power source including the power draw of electronic devices in the imaging system than the amount of power that can be supplied by the conventional power source supplied to an electrical wall outlet.